Systems and methods of the present invention provide for one or more server computers communicatively coupled to a network and configured to: identify, within a data store: a web page including a script tag; a URL in the script tag referencing a location for a second server hosting a script file; and a first hash data in the script tag generated from the script file using a hash function algorithm. The server computer(s) execute a request that accesses the script file and a second hash generated from the script file and stored on the second server computer. If the second hash data does not match the first hash data, execution of the script tag is disabled, and a notification is generated.